Leakage valve and ventilation tube system

ABSTRACT

A leakage valve in a patient ventilation system has a valve housing constructed from a first and second housing parts. The housing parts form a fluid channel with a circular cross-section. The valve housing has first and second connection pieces on the corresponding housing parts. A housing region between the connection pieces projects radially outward. An opening is at the height of the outwardly projecting housing region and enables fluid to pass as a leakage flow. A leakage channel for flow from the leakage valve circulates around part of the valve housing is formed by both housing parts. A catch mechanism includes catch lugs with an end-side detent follow the connection piece and axially engage an outer side of the connection piece. Wall regions between the catch lugs curve along and contact the connection piece inner surface. The housing parts rotate relative to one another in an engaged state.

The present invention relates to a leakage valve according to thepreamble of claim 1 and to a ventilation tube system according to claim13.

TECHNOLOGICAL BACKGROUND

Leakage valves are used for the so-called leakage ventilation. In thiscase, the patient to be ventilated receives a quantity of ventilationgas from a ventilator that is greater than the quantity of ventilationgas used by the patient during breathing. The remainder of this quantityof ventilation gas made available by the ventilator leaves theventilation circuit via the leakage valve. During inspiration, theventilation gas flows through the inner lumen of the leakage valve andat the same time washes all remainders of used air out of the leakagevalve. The ventilator has a precisely defined delivery rate ofventilation gas. This delivery rate can be adjusted on the device sideto the respective patient-dependent consumption rates (e.g., ventilationof an adult or an infant). Ventilators for leakage ventilation areusually precisely adjusted to the leakage quantity determined by theleakage valve. If there are fluctuations in the leakage quantity, theyare not detected and therefore lead to an unwanted impairment of theventilation, which is particularly important when ventilating newborns.

DOCUMENTED PRIOR ART

A leakage valve according to the preamble of claim 1 is known from EP 2428 243 B1. The two housing parts have a mutual gradation and passageopenings in the region of the housing region projecting radiallyoutwards. In this known leakage valve, the two mutually engaged housingparts are supposed to be connected to one another by a clamp connectionin order to avoid a rotation.

Furthermore, from U.S. Pat. No. 5,937,851, a leakage valve is knownwhich also consists of an outer part and an inner part to be engagedtherein. The inner part has spring lugs that engage in the end-side endof the outer part. The outer part is spaced apart from the inner part toform a circulating gap-shaped baffle chamber and has three narrowelevations and one wide elevation on its broad end side, wherein theelevations together with the inner part allow, in regions, a leakage ofCO2-laden breathing air from the baffle chamber. In addition, aplurality of passage openings for an additional air passage from theinside of the leakage valve into the baffle chamber can be provided inthe inner part at a distance from a housing region projecting radiallyoutwards. The inner part and the outer part are supposed to be rotatablerelative to one another. The problem with this design is that in thecase of a mechanical impairment of the leakage valve, considerablefluctuations in the leakage quantity can occur.

Problem Addressed by the Present Invention

The problem addressed by present invention is that of creating a leakagevalve of the type in question, by means of which fluctuations in theleakage quantity can be effectively avoided.

Solution of the Problem

The above problem is solved by a leakage valve with the features ofclaim 1.

Expedient configurations are claimed in the dependent claims.

In contrast to the subject matter of EP 2 428 243 B1, the two housingparts of the leakage valve according to the invention can be rotatedrelative to one another in the engaged state. This has the advantagethat no tensions can occur during use, since the two housing partsrotate relative to one another when mechanical impairments or torsionalloads occur, so that no tensions leading to mechanical impairment canbuild up. This in turn has the effect that far fewer mechanicalimpairments, which lead to a fluctuation in the leakage quantity, canact on the leakage valve. In addition, the leakage valve according tothe invention is characterized by a design that is favorable in terms ofthe production process.

The rotatability of the two housing parts relative to one another isexpediently achieved by providing a gap clearance between the axiallyrunning catch lugs and the axially running inner wall of the firstconnection piece when the two housing parts are in the engaged state.

In the engaged state of the two housing parts, a gap clearance can alsobe provided between the end-side detent of the catch lugs and theend-side end of the first connection piece.

Furthermore, in the engaged state of the two housing parts, a gapclearance can be provided between the axially running outer wall of thecurved wall regions and the axially running inner wall of the firstconnection piece.

The dimension of the gap (gap clearance) for the rotatability of the twohousing parts is essentially 0.08 mm to 0.12 mm (i.e., 0.04 mm to 0.06mm per side based on the diameter), preferably 0.09 mm to 0.11 mm (i.e.,0.045 mm to 0.055 mm per side based on the diameter).

The aforementioned design has the effect that the two housing parts canrotate relative to one another without the application of force, therebyavoiding the occurrence of mechanical stresses on the leakage valveduring use, and the leakage quantity is not subject to any fluctuations.

The fact that a plurality of radially extending webs are provided alongthe perimeter of the second housing part, which delimit throughopenings, creates a particularly advantageous, extensive inflow regionfor the leakage flow into the leakage channel. At the same time, thedesign helps to facilitate the rotatability of the two housing partsrelative to one another.

Except for the webs projecting radially outwards, the housing parthaving the through openings expediently has no gradation.

Since the webs project beyond the curved wall region towards theoutside, it is possible to simultaneously use the webs as supports forthe first housing part.

Expediently, there is a circulating annular space between the inner wallof the expanded housing region and the external end of the respectiveweb. It is thus possible that ventilation gas can also flow around theend side of the web through the annular space located there and fromthere into the leakage channel to the outside, thus additionallystabilizing the leakage quantity.

In the engaged state of the two housing parts, the first housing partexpediently rests, preferably in an abutting manner, on the webs of thesecond housing part. This design has the advantage that, by design, onlyvery low surface friction occurs, which results in an excellentrotatability of the two housing parts relative to one another when thetwo housing parts are rotated relative to one another.

For this purpose, the first housing part expediently has a circulatingstep surface which, in the engaged state of the two housing parts, restson the upper side of the webs.

The first and/or second housing part are preferably designed as onepiece.

Furthermore, the second housing part can have an annular expansion or anannular projection in the region of the expanded housing region, whichextends radially outwards and, together with the inner wall of the firsthousing part, forms the leakage channel leading into the open.

Since the annular expansion is provided with a circulating recess on itsunderside, the mechanical stability of the second housing part isadditionally reinforced overall.

The present invention further relates to a ventilation tube system foruse in leakage ventilation, wherein the ventilation tube systemcomprises a preferably heatable ventilation tube and a leakage valveaccording to claims 1 to 13.

The ventilation tube system is further characterized in that aconnection sleeve for connecting the ventilation tube to the leakagevalve and/or to a functional part is provided on at least one end,preferably on both ends of the ventilation tube.

The leakage valve is expediently located between the connection sleeveand a ventilation aid positioned on the patient.

The leakage valve is expediently located between the connection sleeveand a connector having probe connection means.

DESCRIPTION OF THE INVENTION USING EMBODIMENTS

In the following, an expedient embodiment of the leakage valve accordingto the invention will be described in detail. For the sake of clarity,recurring features are only denoted once. In the drawings:

FIG. 1 shows a greatly simplified schematic depiction of a ventilationsystem for leakage ventilation;

FIG. 2 is a side view of an expedient embodiment of a leakage valveaccording to the invention;

FIG. 3 is a sectional view of the leakage valve according to FIG. 2along the section line A-A;

FIG. 4 is a detailed sectional view in region Z of FIG. 3;

FIG. 5 is a plan view of the upper side of the leakage valve accordingto FIG. 2;

FIG. 6 is a sectional view along the angled intersections B-B of FIG. 5;and

FIG. 7 shows a depiction of the function or the assembly of the leakagevalve according to the invention of FIG. 2 in the engaged state (FIG. 7a), in an exploded view (FIG. 7b ), and also in an exploded view butrotated by 90° with regard to FIG. 7B (FIG. 7c ).

FIG. 1 shows an example of an arrangement for leakage ventilation.Reference sign 15 denotes a ventilation device located on the patient,e.g., a ventilation mask which is provided with a connection piece (notdepicted) and connected to a leakage valve 1 according to the invention.The leakage valve 1 can be followed, e.g., by a connector 24 having aconnection for a probe.

Furthermore, a ventilation tube 13 is provided which, if necessary, cancontain a heating wire provided to keep the ventilation gas within theventilation tube at a specific temperature. However, a heating wire doesnot necessarily have to be present. The ventilation tube 13 has aconnection sleeve 18, 19 at each end. Furthermore, the ventilation tube13 is connected to a humidification chamber 16 of an air humidifier 14via a further connector 23 having a connection for a probe. Speciallyconditioned ventilation gas is kept available in the humidificationchamber 16. The humidification chamber 16 is connected to a fan 22 via aconnecting tube 20 and a connector 21. In order to ensure a specificmoisture content of the ventilation gas located within thehumidification chamber 16, it is connected to a water reservoir 17. Forventilation, the conditioned ventilation gas stored in thehumidification chamber 16 is, due to the overpressure generated by thefan 22, thus conveyed to the patient via the ventilation tube 13. Theventilation gas is inhaled by the patient and exhaled again via theventilation mask. In this case, the patient is supplied with a quantityof ventilation gas that is greater than the quantity used by the patientduring breathing. The remainder of the ventilation gas quantity madeavailable by the ventilation gas leaves the ventilation circuit via theleakage valve 1. During inspiration, the ventilation gas flows throughthe inner lumen of the leakage valve and at the same time washes allremainders of used air out of the leakage valve.

During handling, it can frequently occur that the ventilation tube 13 tothe ventilation device located on the patient, e.g., a ventilation mask,rotates, resulting in torsional forces acting on the leakage valve 1.

FIG. 2 shows one embodiment of a leakage valve according to theinvention. The leakage valve 1 comprises a first round housing part 2and a second round housing part 3, wherein a first connection piece 4 isprovided on the first housing part 2 and a second connection piece 5 isprovided on the second housing part 3. The leakage valve 1 is connectedto the ventilation device 15, e.g., a ventilation mask, by means of theconnection piece 4. The second connection piece 5 is used to connect theleakage valve 1 to the connector 24 having probe connection means ordirectly to the ventilation tube 13. Approximately in the central regionof the leakage valve 1 is an expanding housing region 10 in which acirculating narrow leakage channel 9, cf. FIG. 2, is located for theleakage flow to exit from the leakage valve 1 into the open.

FIG. 3 shows the structural design of the leakage valve 1. The secondhousing part 3 forms the inner lumen of the leakage valve 1, wherein thefirst housing part 2 is arranged on the outside of the second housingpart 3 and engaged in the axial direction via a snap connection. Forthis purpose, the first housing part 2 is pushed over the cylindricalregion of the second housing part 3. The cylindrical region has curvedwall regions 26, between which slots 11 are provided. These slots 11form catch lugs 6 with detents 7 on the upper side which engage with theupper end side of the first housing part 2 and thus immobilize thelatter in an axial holding position. Between the inner wall of the firsthousing part 2 and the outer side of the second housing part 3, anannular leakage channel 9, through which ventilation gas can reach theopen, is provided in the region of the expanding housing region 10.

Furthermore, on the second housing part 3, webs 12 facing radiallyoutwards are provided along the perimeter of the second housing part 3,which delimit through openings 8. Ventilation gas can pass via thethrough openings 8 from the inner lumen of the leakage valve into theinterior of the expanded region 10 and from there into the circulatingleakage channel 9.

The through openings 8 are extensive because they are only delimited bythe radially running webs 12.

In the bottom region of the webs 12, an annular expansion 27 isprovided, the end face of which on the outer perimeter, together withthe inner wall of the first housing part 2, forms the leakage channel 9in the region of the housing expansion 10.

The first housing part 2 has a preferably circulating step surface 25which, in the engaged state of the two housing parts 2, 3, rests on theupper side of the webs 12.

The concept can be seen somewhat more clearly in FIG. 4. The annularexpansion 27 has a circulating recess 28 on its underside, which resultsin a mechanical stiffening of the second housing part 3 or the annularexpansion 27. This mechanical stability prevents the leakage channel 9from changing under mechanical stress, resulting in an impairment of theleakage flow.

The rotatability of the two housing parts 2, 3 relative to one anotherin the engaged state, which can be carried out without exertion offorce, is achieved in that a slight gap clearance is provided betweenthe axially running outer wall of the first housing part 2 in the regionof the catch lugs 6 and the inner wall of the first connection piece 4.A corresponding gap clearance can also be provided between the end-sidedetent 7 of the catch lugs 6 and the end-side end of the firstconnection piece 4. A slight gap clearance can also be provided betweenthe axially running outer wall, the curved wall regions 26 of the firsthousing part 2, and the axially running inner wall of the firstconnection piece 4.

The dimension of the gap (gap clearance) for the rotatability of the twohousing parts is essentially 0.08 mm to 0.12 mm (i.e., 0.04 mm to 0.06mm per side based on the diameter), preferably 0.09 mm to 0.11 mm (i.e.,0.045 mm to 0.055 mm per side based on the diameter). For example, thegap clearance in relation to the diameter is 0.10 mm, i.e., 0.05 mm perside.

FIG. 5 is a plan view of the leakage valve 1. It shows the two oppositecatch lugs 6 having the end-side detents 7 on the upper side of thefirst housing part 2, which overlap the end on the upper side of thesecond housing part 3.

As is clear from FIG. 6, the upper side region of the first housing part2, i.e., the curved wall region 26, is designed to be smooth, i.e.,without a step, up to the upper side of the webs 12. The same applies tothe corresponding region of the first housing part 2 which is arrangedon the outside and forms the first connection piece 4.

As can be seen from FIG. 7a , the two housing parts 2 and 3 of theleakage valve 1 according to the invention can be rotated relative toone another very easily in the engaged state. Thus, no torsional forcescan build up on the housing of the leakage valve 1 if, e.g., theventilation tube 13 is rotated.

FIGS. 7b and 7c are exploded views of the leakage valve. The respectiveregion of the through openings 8 provided along the perimeter, throughwhich breathing gas can pass from the inner lumen of the leakage valve 1into the annular space 29 and from there into the annular leakagechannel 9 (cf. e.g., FIG. 3), is clearly visible.

The design according to the invention also makes it possible to producethe housing parts 2 and 3 in a simple manner in one piece from plasticin an injection molding process.

It must expressly be noted that sub-combinations of the describedfeature complexes and embodiments are also regarded as expresslyincluded in the subject matter of the present invention.

LIST OF REFERENCE SIGNS

-   1 Leakage valve-   2 First housing part-   3 Second housing part-   4 First connection piece-   5 Second connection piece-   6 Catch lug-   7 Detent-   8 Through opening-   9 Leakage channel-   10 Expanded housing region-   11 Slot-   12 Web-   13 Ventilation tube-   14 Humidifier-   15 Ventilation device-   16 Humidification chamber-   17 Water reservoir-   18 Connection sleeve-   19 Connection sleeve-   20 Connecting tube-   21 Connector-   22 Fan-   23 Connector having probe connection means-   24 Connector having probe connection means-   25 Step surface-   26 Curved wall region-   27 Annular expansion-   28 Recess-   29 Annular space

1. Leakage valve (1) for use in a patient ventilation system comprisinga valve housing constructed from a first (2) and a second housing part(3) and preferably consisting of plastic, wherein the housing parts (2,3) form a fluid channel preferably with a circular cross section,wherein the valve housing comprises the following: a first connectionpiece (4) on the first housing part (2); a second connection piece (5)on the second housing part (3); and a housing region (10) arrangedbetween the two connection pieces (4, 5) and projecting radiallyoutwards; at least one through opening (8) which is arrangedapproximately at the height of the outwardly projecting housing region(10) and enable(s) the fluid to pass out of the fluid channel in theform of a leakage flow; a leakage channel (9) for the outlet of theleakage flow out of the leakage valve (1), which is likewise arrangedapproximately at the height of the outwardly projecting housing region(10), circulating at least around a part, preferably around the entireperimeter of the valve housing, and preferably formed by both housingparts (2, 3); a catch mechanism, by means of which the two housing parts(2, 3) can be connected to one another, wherein at least one, preferablya plurality of catch lug(s) (6) with an end-side detent (7) and curvedaccording to the inner radius of the connection piece (4 or 5) areprovided as a catch mechanism, which extend along the connection piece(4 or 5) in contact with the inner side in the engaged state, engage onthe outer end side of the connection piece (4 or 5) by their detent (7)and guarantee an axial engagement, and wall regions (26) are providedbetween the catch lugs (6), which are curved according to the innerradius of the connection piece (4 or 5), and which are in contact withthe inner surface of the connection piece (4 or 5), characterized inthat the two housing parts (2, 3) can be rotated relative to one anotherin the engaged state.
 2. Leakage valve according to claim 1,characterized in that, in the engaged state of the two housing parts (2,3), a gap clearance is provided between the axially running outer wallof the catch lugs (6) and the axially running inner wall of the firstconnection piece (4).
 3. Leakage valve according to claim 1 or 2,characterized in that, in the engaged state of the two housing parts (2,3), a gap clearance is provided between the end-side detent (7) of thecatch lugs (10) and the end-side end of the first connection piece (4).4. Leakage valve according to the preceding claims, characterized inthat, in the engaged state of the two housing parts (2, 3), a gapclearance is provided between the axially running outer wall of thecurved wall regions (26) and the axially running inner wall of the firstconnection piece (4).
 5. Leakage valve according to the precedingclaims, characterized in that a plurality of radially running webs (12)are provided on the second housing part (3) along the perimeter, betweenwhich the through openings (8) are provided or which laterally delimitthe through openings (8).
 6. Leakage valve according to claim 5,characterized in that the webs (12) project beyond the curved wallregions (26) towards the outside.
 7. Leakage valve according to claim 5or 6, characterized in that there is a circulating annular space (29)between the inner wall of the expanded housing region (10) and the outerend of the respective web (12).
 8. Leakage valve according to claims 5to 7, characterized in that, in the engaged state of the two housingparts (2, 3), the first housing part (2) rests on the webs (12). 9.Leakage valve according to claims 5 to 8, characterized in that thefirst housing part (2) has a circulating step surface (25) which restson the upper side of the webs (12) in the engaged state of the twohousing parts (2, 3).
 10. Leakage valve according to the precedingclaims, characterized in that the first (2) and/or second housing part(3) are designed as one piece.
 11. Leakage valve according to thepreceding claims, characterized in that the second housing part (3) hasan annular expansion (27) in the region of the expanded housing region(10).
 12. Leakage valve according to claim 11, characterized in that theannular expansion (27) is provided with a circulating recess (28) on itsunderside.
 13. Ventilation tube system for use in leakage ventilation,comprising a, preferably heatable, ventilation tube (13) and a leakagevalve (1) according to the preceding claims.
 14. Ventilation tube systemaccording to claim 13, characterized in that a connection sleeve (18,19) for connecting the ventilation tube (13) to the leakage valve (1)and/or a functional part is provided on at least one end, preferably onboth ends of the ventilation tube (13).
 15. Ventilation tube systemaccording to claims 12 to 14, characterized in that the leakage valve(1) is located between the connection sleeve (18) and a ventilationdevice (15) positioned on the patient.
 16. Ventilation tube systemaccording to claims 12 to 15, characterized in that the leakage valve(1) is located between the connection sleeve (18) and a connector (24)having probe connection means.